Mixel is an iPhone app that lets you splice up multiple photos into a single collage with beautiful filters.

What it is: Take pictures in the Mixel app or upload them from your mobile camera. Then create a single-image collage out of them. The collage pieces can be shuffled, and Instagram-like filters can be added.

Turf is a new iPhone game that looks like SimCity but uses check-ins like Foursquare.

What it is: Take over the buildings in your city virtually. Turf lets you own buildings you check-in to, battle other users for their properties, and advance to new levels. It has elements of Foursquare, SimCity and Mario.

Date Founded: 2011, launched August 2012

Based in: New York, NY (WeWork Labs)

Founded By: Michael Tseng

Funding: $600,000 seed round led by RRE

Why you should care: Turf was one of the first buzzy Kickstarter projects. The app is exceptionally beautiful because its founder Tseng, doesn't have a typical tech background. He is a graduate of Savannah College of Art and Design and was a creative at advertising agency Crispin Porter + Bogusky.

Stamped is a recommendation app. It lets people list and follow other users' favorite things, such as restaurants and songs.

What it is: Stamped is a mobile app that lets you bookmark your favorite movies, books, songs and more. It also lets you follow other people, including celebrities like Ellen DeGeneres, so you can check out their favorite things too.

But really, there is no place for the things you really love, except on your Facebook profile page. "Ellen talks about her favorite things on her show all the time; now she has a place to put them," says CEO Robby Stein.

Square is a mobile payment solution. It's a credit card swiper that attaches to mobile devices so payments can be collected on the go.

What it is: Square is a credit card reader that attaches to mobile devices. Credit cards can be swiped and payments collected on-the-go.

Date Founded: February 2009

Based in: San Francisco, CA

Founded By: Jack Dorsey

Funding: $166 million

Why you should care: Jack Dorsey has been compared to Steve Jobs as one of the most innovative entrepreneurs in the world. Prior to Square he co-founded Twitter. In June, Square said it was handling $6 billion per year in payments. Now it has a deal with Starbucks, so its business may soon double in size.

Runkeeper helps you track and achieve fitness goals on your phone

What it is: A fitness app that lets you set goals and track your workouts. It also has a playlist feature so you don't have to have another app open while you run, walk or bike.

Date Founded: 2008

Based in: Boston, MA

CEO: Jason Jacobs

Funding: $11.5 million

Why you should care: While there are a lot of running apps and products on the market, RunKeeper is one of the most personal, goal-oriented tracking companies out there. It's also one of the most accurate. Mark Zuckerberg recently called out RunKeeper as a Facebook-integrated startup that's "killing it."

Foursquare lets you check-in to places you visit and it shows you places your friends have been recently.

What it is: A location-based app that lets you check-in to places and see where friends have gone lately.

Date Founded: March 2009

Based in: New York, NY (Soho)

Founded By: Dennis Crowley, Naveen Selvadurai

Funding: $71.4 million

Why you should care: Foursquare is one of the largest independent iPhone apps with more than 20 million users. Although its growth has slowed significantly and it's still figuring out a revenue model, the size of its user-base, its brand name, and the location data it stores makes it a valuable startup to watch.

Path is an ex-Facebooker's vision of what a mobile social network should look like.

Kevin Smith, Business Insider

What it is: Path is a mobile social network. Founded by former Facebook executive Dave Morin, it's a more intimate network that limits the number of people you can be connected to. Users post things like exercise schedules and sleep cycles on their pages.

Date Founded: May 2012

Based in: San Francisco, CA

Founded By: Dave Morin

Funding: $41.2 million

Why you should care: Dave Morin is well known in tech for his angel investments, his former positions at Facebook and Apple, and now as an entrepreneur. Path struggled as an entirely different app in its first year, but it had a successful pivot in November 2011. Since then, users have clamored onto the app. There are 1.1 million active monthly users according to AppData, and more than 300,000 daily active users.

Paper is a beautiful drawing app that turns an iPad into a piece of paper on which you can sketch, paint or even add water color.

What it is: Paper is an iPad app that turns your iPad into, well, paper. It's free to download, but if you want a complete tool set full of colors, brushes, pens, pencils and kinds of paint (water color, etc), you'll need to pay $7.99. It's the most detailed way to draw something with either your finger or a stylus.

Date Founded: March 2012

Based in: New York, NY

Founded By: Georg Petschnigg

Funding: n/a

Why you should care: Some investors see Paper's opportunity as the iPad equivalent of Adobe's Creative Suite. We hear a few notable VC firms including Union Square Ventures were interested in funding Paper, but Petschnigg couldn't decide if he wanted to raise a round or not. With more than 1.5 million people using his app in the first two weeks, many of whom are paying the $7.99, it's easy to understand why Petschnigg might want to wait.

Checkmark is a location-based reminder app that pings you when you're nearby something you've scheduled

What it is: A new development company founded in February 2012, Snowman, produced Checkmark. "The app takes advantage of the iPhone's geofencing feature to alert you of tasks when you enter and exit a particular location," SAI's Kevin Smith writes in the App 100 list.

Date Founded: July 2012

Founded By: Ryan Cash and Jordan Rosenberg via Snowman

Funding: Bootstrapped

Why you should care:"It's not a new concept, but Checkmark does it a lot better than the iPhone's built-in Reminders app...It rivals our old favorite Clear and Apple's own Reminders," Smith writes.

Rovio is the maker of hit iPhone and iPad games, Angry Birds.

Why you should care: Rovio's Angry Birds games continue to be big hits. In early May, Rovio announced that its Angry Birds games had been downloaded more than 1 billion times. Its revenue also increased from $10 million generated in 2010 to $106.3 million in 2011 between app purchases and merchandise sales.

Uber lets you hail a black car from your phone.

What it is: Hail a black car, hybrid or -- in some cities -- a cab from your smart phone. The Uber app shows you your current location (or you can set a pickup location) and sends a car to get you in minutes.

Date Founded: 2009

Based in: San Francisco

Founders: Travis Kalanick and Garrett Camp

Funding: $44.5 million

Why you should care: Uber is creating a new form of transportation. Having used Uber in multiple locations, there's a real need for reliable door to door transportation in just about every major city besides Manhattan, which already has transportation down pat.

The convenience of Uber is really key. No cash is exchanged because Uber keeps your credit card on file, and it's all coordinated via the mobile app.

Vyclone lets people who are shooting the same event on their phones collaborate on mobile videos.

Steve Kovach, Business Insider

What it is: Vyclone is a mobile video app that lets multiple people collaborate on a single video from the same event. So if you're at a concert and are recording a short clip next to someone else who's doing the same thing, you can use Vyclone to mash your videos together.

Date Founded: 2012

Based in: Los Angeles

Founders: David King Lassman Joe Sumner

Funding: $2.7 million

Why you should care: First, Joe Sumner is Sting's son. So there's that. Be more importantly, there's a lot happening in the collaborative video and photo space. Mixel came out swinging on the photo front, Vyclone is trying to own it for videos.

Vyclone is an interesting way for people to create videos using multiple angles, just like big networks, without having to own more than one camera. Ashton Kutcher saw Vyclone and told the founders it could be a game-changer if done right. He sent them a term sheet two days later.

Flipboard is a social news reader for mobile devices

Steve Kovach, Business Insider

What it is: Flipboard is a mobile news reader that uses social media to curate personalized links for its users.

Still, Flipboard might have a tough road ahead. Mike McCue had to step down from Twitter's board in August because the social media platform is positioning itself to be a Flipboard competitor. If Twitter pulls its API from Flipboard, the startup could be in trouble. Otherwise, it's a great way to consume customized news.

Brewster makes your phone's contact list much more social and updates it in real time.

What it is: Brewster is a smart contact list app for your iPhone. Traditional contact lists have to be updated by you manually and often store just a name and phone number. Brewster uses social media profiles to fill in and update contact information for you.

Date Launched: July 2012

Based in: New York

Founder: Steve Greenwood

Funding: Undisclosed amount from Union Square Ventures and others

Why you should care: So many people downloaded Brewster the day it launched that the app crashed. Since its buzzy launch, users have fallen to about 4,000 DAUs according to AppData.

But, like Instagram took Apple's simple camera app and made it better, there's an opportunity to do that with the traditional contact list app. Brewster's founder Steve Greenwood has been trying to find a good solution for the past seven years, so he's well positioned to figure it out.

Waze connects cars on the road via a social traffic and navigation app. Drivers can alert each other of road blocks up ahead and the app is updated in real time.

What it is: A social navigation app that lets other drivers tell you where traffic is and what's holding things up.

Date Founded: 2008

Based in: Israel with an office in Palo Alto, CA

Founders: Uri Levine, Ehud Shabtai and Amir Shinar

Funding: $67 million

Why you should care: In July, Waze announced 20 million users. Facebook executives recently met with the Israeli startup, which sparked rumors that an acquisition could be in the works. Either way, Waze is a lifesaver when you're sitting in traffic and have no idea why you're stalled. It also tells you where police are sitting on the road and it's one of the best real-time navigation tools available.

Romotive turns smart phones and iPads into robots

Romo, the iPhone robotKane Hsieh

What it is: Romotive turns your iPhone or iPad into a robot that can be controlled through another mobile device. It uses emoticons and sounds to give the robot personality, kind of like a Furby.

Date Founded: 2011

Based in: Las Vegas, NV

Founders: Keller Rinaudo, Phu Nguyen, Peter Seid

Funding: $1.62 million

Why you should care:Romotive is turning smart phones into a brain that powers inanimate objects. In a sense, it brings them to life. Rinaudo says he wants to place a robot in every household and his team is developing a robot API.

Orbotix is another startup that's trying to turn iPhones into robots. It's product, Sphero, is an iPhone controlled ball that's sold in Apple stores.

Why you should care: Sphero makes for a pretty cool toy. You can imagine driving a dog, cat or even a child crazy with a ball they can never catch. It also has much more serious possibilities. For example, it could also be a groundbreaking spy tool because you can send a tiny ball places people can't go. Orbotix recently struck a deal with Apple, and its products are being sold in stores nationally.